UNTIL uses only utc when to_ical

[sysmugen]

Hi.

Why ice_cube uses this:

      def build_ical(builder)
        builder['UNTIL'] << IcalBuilder.ical_utc_format(time)
      end

but not this:

      def build_ical(builder)
        builder['UNTIL'] << IcalBuilder.ical_format(time, force_utc)
      end

I use Japan time zone and when I use UNTIL it creates wrong UNTIL entry. See below.

start_time = Time.current
end_time = Time.current+2.hours
rule = IceCube::Rule.daily(1)
rule = rule.until(end_time)
IceCube::Schedule.new(start_time, end_time: end_time) { |s| s.add_recurrence_rule(rule) }.to_ical

Produces
"DTSTART;TZID=JST:20221008T225632\nRRULE:FREQ=DAILY;UNTIL=20221008T155635Z\nDTEND;TZID=JST:20221009T005635"

Any ideas?